Interactive Baking Tool
Cake Tin Conversion Calculator
Convert your cake recipe between different tin shapes and sizes in seconds. Whether your recipe calls for a round cake tin or a square cake pan, we have you covered.
Original Recipe Tin
Your Target Tin
Scale an Ingredient
Enter any amount (grams, ml, ounces, or number of eggs) to see the mathematically scaled equivalent. For eggs, round to the nearest whole egg or whisk and measure.
How to Use the Cake Tin Conversion Calculator
Select original tin
Choose the shape and enter the dimensions specified in your original recipe.
Select target tin
Enter the shape and dimensions of the cake tin you actually want to use.
Get recipe multiplier
The calculator will instantly tell you how much to multiply your ingredients by.
Scale ingredients
Use the ingredient scaler box to quickly calculate your new measurements.
How Cake Tin Conversion Works
Round to Square Cake Tin Conversion
A 20 cm round tin has a base area of about 314 cm²; a 20 cm square tin has 400 cm². The square therefore has about 27% more base area. At the same batter depth, that means about 27% more mixture. Different tin depths need a capacity comparison as well.
This cake tin converter also works for recipes that use the US term 'cake pan'.
Cake Tin Depth and Baking Time
A deeper layer of batter may take longer to bake; a shallower layer may finish sooner. Keep the recipe's oven setting unless a tested adjustment is supplied, and use its doneness cues. The ingredient multiplier does not calculate a verified baking time.
Common UK Cake Tin Equivalents
| Original Tin | Similar-Capacity Alternative | Approx. Multiplier |
|---|---|---|
| 15 cm (6") Round | 13 cm (5") Square | 0.95× |
| 20 cm (8") Round | 18 cm (7") Square | 1.03× |
| 23 cm (9") Round | 20 cm (8") Square | 0.96× |
| 25 cm (10") Round | 23 cm (9") Square | 1.08× |
Note: Calculations assume tins are of identical depth.
Frequently Asked Questions
Is a cake tin the same as a cake pan?
In most baking recipes, yes. UK recipes usually say 'cake tin', while US recipes commonly use 'cake pan'. For this calculator, both terms refer to the baking container whose shape and size you want to convert.
How do I scale ingredient quantities for a new tin?
Multiply each ingredient in your recipe by the recipe multiplier shown in the calculator. For example, if your multiplier is 1.25× and your recipe calls for 200g of flour, you will need 250g of flour (200 × 1.25).
How does cake tin depth affect recipe conversion?
If both tins have the same depth, you only need to compare their surface areas. However, if your target tin is shallower or deeper, you should adjust for volume to ensure the batter fits properly without overflowing or baking too thinly.
Can I use a 9-inch tin instead of an 8-inch tin?
For equal-depth round tins, exact 9-inch and 8-inch diameters give a multiplier of (9 ÷ 8)² = 1.265625, or about 1.27. Exact 23 cm and 20 cm diameters give (23 ÷ 20)² = 1.3225, or about 1.32. Rounded inch and centimetre labels are not identical measurements; use the tin's actual inside dimensions.
Do I need to adjust the baking time when changing tin sizes?
Possibly. Depth, tin material and the recipe affect baking time, so there is no fixed adjustment. Keep the stated oven setting unless you have a tested alternative and check the centre using the recipe's doneness cues.